Abstract
Companion animals, particularly dogs and cats, are becoming essential members of modern households. They consistently share both indoor and outdoor spaces with their owners, resulting in a substantial overlap in living environments. Although public health concerns associated with companion animals receive considerable attention, their potential role as sentinel species remains underestimated. This role aligns with the One Health concept, which emphasizes the interconnection and mutual influence of human, animal and ecosystem health. In this review, we discuss the sentinel role of companion dogs and cats from environmental hazards and parasitic infections. We also highlight their role in zoonotic diseases, with rabies and vector-borne diseases (VBDs) as examples. We aim to propose new ideas and methodologies to control and prevent these issues.